1. V. N. Obridko and B. D. Shelting, in Modern Problems of the Solar Cycles, Ed. by V. I. Makarov and V. N. Obridko (GAO, St. Petersburg, 1997), p. 193.
2. V. N. Obridko and B. D. Shelting, Solar Phys. 184, 187 (1999).
3. V. N. Obridko and B. D. Shelting, in New Solar Activity Cycle: Observational and Theoretical Aspects, Ed. by V. I. Makarov and V. N. Obridko (GAO, St. Petersburg, 1998), p. 137.
4. V. N. Obridko and B. D. Shelting, Astron. Zh. 77, 124 (2000).
5. J. T. Hoeksama, J. M. Wilcox, and P. H. Sherrer, J. Geophys. Res. 87, 10331 (1982).